package Dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: Home-pc
 * Date: 2023-10-28
 * Time: 14:50
 */
//使用这个类封装对user表的增删改查
public class UserDao {
    //根据userId查询用户信息
    public User getUserById(int userId){
        Connection connection=null;
        PreparedStatement statement=null;
        ResultSet resultSet=null;

        try {
            connection=DBUtil.getConnection();
            String sql="select * from user where userId = ?";
            statement=connection.prepareStatement(sql);
            statement.setInt(1,userId);
            resultSet=statement.executeQuery();
            if(resultSet.next()){
                User user=new User();
                user.setUserId(resultSet.getInt("userId"));
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));
                return user;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }
        return null;
    }

    //根据username来查询用户信息
    public User getUserByName(String username){
        Connection connection=null;
        PreparedStatement statement=null;
        ResultSet resultSet=null;

        try {
            connection=DBUtil.getConnection();
            String sql="select * from user where username = ?";
            statement=connection.prepareStatement(sql);
            statement.setString(1,username);
            resultSet=statement.executeQuery();
            if(resultSet.next()){
                User user=new User();
                user.setUserId(resultSet.getInt("userId"));
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));
                return user;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }
        return null;
    }
}
